RU2744910C2 - User terminal and a radio communication method - Google Patents

Abstract

FIELD: wireless communication.

SUBSTANCE: invention relates to the field of wireless communication. A user terminal in accordance with one aspect of the present invention communicates in a cell that uses a reduced TTI with TTI duration of less than 1 ms, and/or a cell in which communication is controlled using reduced processing time that is shorter than the processing time in the existing LTE system. The user terminal has a measurement section designed to measure CSI using a reference CSI resource, and a transmission section designed to transmit CSI in a given subframe. The reference CSI resource is in a subframe preceding the said specified subframe by a period, which is shorter than the specified time period.

EFFECT: invention ensures proper measurements and transmission of channel state information (CSI) even when using reduced transmission time intervals (TTI) and /or reduced processing time.

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Description

The technical field to which the invention relates

The present invention relates to a user terminal and a radio communication method in next generation mobile communication systems.

State of the art

Long Term Evolution (LTE) specifications were proposed in the Universal Mobile Telecommunications System (UMTS) network, aimed at further increasing the data transfer rate, reducing latency, etc. (see non-patent document 1). For an even greater bandwidth and speed increase compared to LTE (also called LTE version 8 or LTE version 9), the specifications of the advanced LTE system (eng.LTE-advanced, LTE-A, also called LTE version 10, LTE version 11 or LTE version 12); LTE successor systems (also called, for example, Future Radio Access (FRA), 5th generation mobile communication system, 5G), New Radio, NR), new radio access (NX), future generation radio access (FX), LTE version 13, LTE version 14, LTE version 15 and / or later).

LTE 10/11 introduces carrier aggregation (AH), in which multiple elementary carriers (EH) are combined, to expand bandwidth. Each EN is configured using the LTE Release 8 frequency band as one element. With AH, the user terminal (English User Equipment, UE)) is configured to use a plurality of AH of one radio base station (English eNodeB, eNB)).

LTE Release 12 introduces dual connection (DS), in which a user terminal is configured to use multiple cell groups (HS) formed by different radio base stations. Each cell group contains at least one cell (CE). With DS, many EN of different base radio stations are combined, therefore, DS is also called inter-station carrier aggregation.

When using AH in the user terminal, a highly reliable primary cell (English Primary Cell, PCell), which provides the connection, and an auxiliary secondary cell (English Secondary Cell, SCell) are configured.

First, the UE can connect to PCell, then SCells can be added as needed. PCell is a separate cell (autonomous cell) that supports Radio Link Monitoring (RLM), Semi-Persistent Scheduling (SPS), etc. SCell is a cell that the UE uses in addition to PCell.

In existing LTE systems (eg, LTE versions 8-12), uplink signals are mapped to the appropriate RF resources and transmitted from the UE to the eNB. Uplink user data is transmitted using the Physical Uplink Shared CHannel (PUSCH). Uplink Control Information (UCI) is also transmitted using PUSCH if it is jointly transmitted with upstream user data; in the case of a separate transmission, the UCI is transmitted using the Physical Uplink Control CHannel (PUCCH).

The UCI contains ACK / NACK information in response to a Physical Downlink Shared CHannel (PDSCH), a scheduling request, Channel State Information (CSI), and so on. The delivery confirmation information may be called HARQ-ACK (Hybrid Automatic Repeat reQuest Acknowledgment, Hybrid Automatic Repeat Request Acknowledgment, ACK / NACK (A / N) signal, retransmission control information, etc.).

CSI is information based on the current states of the downlink channel, and contains, for example, a Channel Quality Indicator (CQI), a Precoding Matrix Indicator (PMI), a precoding type indicator (Eng. Precoding Type Indicator, PTI), Rank Indicator (RI), etc. CSI is transmitted from the UE to the eNB periodically or aperiodically.

Periodic CSI (P-CSI) refers to the type of CSI that is transmitted from the UE periodically based on the period and resources reported from the radio base station. Aperiodic CSI (A-CSI) refers to the type of CSI that is transmitted from the UE in response to a CSI transmission request from the radio base station (also called a flip-flop, CSI flip-flop, CSI request, etc.).

The CSI trigger is included in an uplink scheduling grant (hereinafter also referred to as an uplink grant) transmitted in a Physical Downlink Control Channel (PDCCH). In response to the CSI trigger contained in the upstream grant, the UE reports A-CSI using the PUSCH indicated by the upstream grant. Such a message is also referred to as an A-CSI message.

In existing systems (LTE versions 8-12), frequency division duplex (FDD) has been introduced, in which the downstream transmission and upstream transmission are carried out in different frequency bands, and the time division duplex Duplex TDD), in which the downstream and upstream transmissions are in the same frequency band alternately in time.

In existing systems, the Transmission Time Interval (TTI) used for transmission / reception in the eNB and UE is set to 1 ms (millisecond) and is controlled accordingly. The transmission time slot is also referred to as a communication time slot, and in LTE versions 8-12 TTI is a subframe duration.

List of cited materials

Non-patent documents

Non-Patent Document 1: 3GPP TS 36.300 "Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); General Description; Phase 2" (3GPP TS 36.300 "Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall Description; Stage 2 ").

Disclosure of the essence of the invention

Technical problem

It is anticipated that future radio systems (eg, 5G, NR, etc.) will provide a variety of radio services to meet interdependent needs (eg, ultra high speed, high throughput, ultra low latency, etc.).

For example, a 5G system is being developed to provide such radio communication services as enhanced mobile broadband (eMBB), Internet of Things (loT), machine type communication, MTS), machine-to-machine communication (M2M), Ultra Reliable and Low Latency Communications (URLLC), etc. It should be noted that machine-to-machine communication (M2M), depending on the devices that communicate, can be called a connection between devices (Device To Device, D2D), communication between vehicles (Vehicle To Vehicle, V2V), etc. To meet the requirements, the fulfillment of which is necessary for the implementation of the above various types of communication, a new access scheme for communication is being developed (new radio access technology (RAT).

In order to provide complete communication services in these future radio communication systems, research is underway to reduce communication delay (lag). For example, research is underway to make the transmission time interval (TTI), which serves as the smallest time unit in scheduling, shorter than 1 ms, as used in existing LTE systems (LTE versions 8-12), and communicate using such TTIs. (which may be called, for example, abbreviated TTIs or sTTIs). Research is also underway to reduce processing time compared to existing LTE systems.

However, in existing LTE systems, communication timing is controlled in units of subframes (in units of 1 ms duration), and it has not yet been decided how to manage communication by introducing reduced TTIs and / or reducing processing time.

For example, as noted above, existing LTE systems provide operations for transmitting periodic channel state information (P-CSI) and aperiodic channel state information (A-CSI). With the introduction of reduced TTIs and / or reduced processing time, the question arises of how to control the transmission and reception of P-CSI and A-CSI. Thus, there is a need for a control method that enables proper communication even when using reduced TTIs and / or reduced processing time. Until the UE, eNB and / or other elements support adequate control methods, for example, disadvantages such as reduced communication quality, communication system throughput, spectral efficiency, etc. can arise.

An object of the present invention, made in view of the above, is to provide a user terminal and a radio communication method that can support proper CSI measurements and reporting even when using reduced TTIs and / or reduced processing time.

Solution to the problem

A user terminal in accordance with one aspect of the present invention communicates in a cell that uses a reduced transmission time interval (TTI) with a duration of less than 1 ms, and / or in a cell in which communication is controlled using a reduced processing time shorter than processing in the existing LTE system, and this user terminal comprises a measurement section configured to measure channel state information (CSI) using the CSI reference resource, and a transmission section configured to transmit CSI in a given subframe, while it is provided to find the reference resource CSI in a subframe earlier than this predetermined subframe by a period that is shorter than the predetermined time period.

The technical result of the invention

The present invention makes it possible to maintain proper CSI measurements and transmission even when using reduced TTIs and / or reduced processing time.

Brief Description of Drawings

FIG. 1 is a diagram of an example of sTTIs.

FIG. 2 shows examples of communication using nTTI and sTTI.

FIG. 3A is a diagram of a configuration example of sTTIs, and FIG. 3B is a diagram of another sTTI configuration example.

FIG. 4A is a diagram of a first sTTI setting example, FIG. 4B is a diagram of a second sTTI setting example, and FIG. 4C is a diagram of a third example of setting sTTIs.

FIG. 5 is a diagram of examples of reference CSI resources for use for P-CSI transmission in existing systems.

FIG. 6 is a diagram of examples of reference CSI resources for use for A-CSI transmission in existing systems.

FIG. 7 is a diagram of examples of reference CSI resources for use for A-CSI transmission in accordance with the first embodiment of the present invention.

FIG. 8 is a diagram of another example of reference CSI resources for use for A-CSI transmission in accordance with this first embodiment.

FIG. 9 is a diagram of examples of reference CSI resources for use for P-CSI transmission in accordance with a second embodiment of the present invention.

FIG. 10 is a diagram of another example of reference CSI resources for use for P-CSI transmission in accordance with this second embodiment.

FIG. 11 is a diagram of examples of reference CSI resources for use for A-CSI transmission in accordance with the second embodiment.

FIG. 12 is a diagram of other examples of reference CSI resources for use for A-CSI transmission in accordance with the second embodiment.

FIG. 13 is a diagram of an example of the general structure of a radio communication system in accordance with one embodiment of the present invention.

FIG. 14 is a diagram of an example of a general structure of a radio base station in accordance with one embodiment of the present invention.

FIG. 15 is a diagram of an example of a functional structure of a radio base station in accordance with one embodiment of the present invention.

FIG. 16 is a diagram of an example of a general structure of a user terminal in accordance with one embodiment of the present invention.

FIG. 17 is a diagram of an example of a functional structure of a user terminal in accordance with one embodiment of the present invention.

FIG. 18 is a diagram of an example hardware structure of a radio base station and user terminal in accordance with one embodiment of the present invention.

Implementation of the invention

(Reducing communication delay)

As noted above, future radio communication systems are expected to reduce communication latency, and research is underway to reduce signal transmission / reception processing time compared to existing LTE systems. To reduce processing time, it is possible, as in existing LTE systems, to control communication based on subframes, but it is possible to specify a shorter processing time than in existing LTE systems.

As used herein, processing time in existing LTE systems (eg, versions 8-12) may be referred to as conventional processing time. Processing times that are shorter than normal processing times may be referred to as reduced processing times. The UE in which the reduced processing time is set controls the transmission / reception of predetermined signals (eg, encoding) such that these signals are transmitted / received at earlier times than the transmission / reception times defined in existing LTE systems. Reduced processing time can be set for specific operations (for different elements, for example, per signal, per operation, etc.) or for all operations.

For example, in existing systems, the UE, upon receiving an uplink grant in subframe n, transmits uplink data in a subframe following a predetermined time period (eg, in subframe n + k, where k is greater than or equal to four). However, if a reduction in processing time is specified, the UE controls so that uplink data is transmitted at times before subframe n + k (eg, in subframe n + k ', where k' is less than four). In this case, the time required for transmitting uplink data can be shortened even by controlling the communication as before in subframe units.

It should be appreciated that the reduced processing time may be pre-specified in the specification, or may be communicated (specified, prescribed, etc.) to the user terminal via higher layer signaling (e.g., broadcast information, Radio Resource Control (RRC) signaling) ) and / or physical layer signaling (eg, Downlink Control Information (DCI)).

In addition, as a method for reducing communication latency, it is possible to introduce shortened TTIs with a duration less than the subframe duration (1 ms) of existing LTE systems and control the transmission and reception of signals using the shortened TTIs. In this document, a TTI with a time duration of 1 ms, the same as an existing subframe (eg, TTI in LTE versions 8-12), may be referred to as a normal TTI (nTTI). TTI is shorter than nTTI can be called shortened TTI (sTTI).

By using sTTIs, the processing margin (eg, encoding, decoding, etc.) in the UE and / or eNB is increased, which makes it possible to reduce processing latency. In addition, by using sTTI, it is possible to increase the number of user terminals that can be served by a unit of time (eg, 1 ms). Next, referring to FIG. 1-4 describe sTTIs.

FIG. 1 is a diagram for explaining an example of transmission time intervals (TTI) in existing systems (LTE versions 8-12). As shown in FIG. 1, nTTI has a time duration of 1 ms. NTTI is also called a subframe and consists of two time slots. TTI is a time unit for the transmission of one channel-coded data packet (transport block) and is an item for data processing in scheduling, link adaptation, etc.

As shown in FIG. 1, on the downlink using normal cyclic prefix (CPU), nTTI contains 14 Orthogonal Frequency Division Multiplexing (OFDM) symbols (seven OFDM symbols per slot). Each OFDM symbol has a time duration (symbol duration) of 66.7 μs, and a normal CPU is added with a duration of 4.76 μs. Since the symbol duration and the subcarrier spacing are reciprocal, for a symbol duration of 66.7 μs, the subcarrier spacing is 15 kHz.

On the uplink using the normal cyclic prefix, nTTI is configured to contain 14 symbols of the Single Carrier Frequency Division Multiple Access (SC-FDMA) scheme (seven SC-FDMA symbols per slot). Each SC-FDMA symbol has a time duration (symbol duration) of 66.7 µs, and a normal CPU is added with a duration of 4.76 µs. Since the symbol duration and the subcarrier spacing are reciprocal, for a symbol duration of 66.7 μs, the subcarrier spacing is 15 kHz.

When using an enhanced CPU, nTTI can contain 12 OFDM symbols (or 12 SC-FDMA symbols). In this case, each OFDM symbol (or each SC-FDMA symbol) has a duration of 66.7 µs, and an extended CPU with a duration of 16.67 µs is added.

FIG. 2 shows an example of communication using nTTIs and sTTIs. FIG. 2 represents a cell (EN # 1) using nTTI (1 ms) and a cell (EN # 2) using sTTI. When using sTTI, the sub-carrier spacing can be made different from the nTTI sub-carrier spacing. As shown in FIG. 2, the subcarrier spacing on EN # 2 is greater than that on EN # 1, and a wider bandwidth is used.

(Examples of abbreviated TTI configurations)

FIG. 3 presents diagrams of examples of sTTI configurations. FIG. 3A is a diagram of a configuration example of sTTIs, and FIG. 3B is a diagram of another sTTI configuration example. As shown in FIG. 3A and 3B, sTTIs have a time duration (TTI duration) of less than 1 ms. STTI can be composed of one TTI duration or multiple TTI durations, multiplied by 1 ms, e.g. 0.5 ms, 0.25 ms, 0.2 ms, 0.1 ms, etc.

Alternatively, when the nTTI for normal CPUs contains 14 symbols, the sTTI can be composed of one TTI duration or multiple TTIs that are multiples of 1/14 ms, for example, 7/14 ms, 4/14 ms, 3/14 ms, 2 / 14 ms, 1/14 ms, etc.

When the nTTI for extended CPUs contains 12 symbols, the sTTI can be one TTI, or multiple TTIs in multiples of 1/12 ms, for example, 6/12 ms, 4/12 ms, 3/12 ms, 2/12 ms. 1/12 ms, etc.

It should be appreciated that the sTTI only needs to have a shorter time duration than the nTTI and is not limited to the above TTI durations. The use of normal CPUs or extended CPUs in sTTI can, as in conventional LTE, be specified using higher layer signaling such as broadcast information and RRC signaling. An sTTI can be introduced in this way while maintaining compatibility (synchronization) with a 1 ms nTTI.

Note that although FIG. 3A and 3B illustrate examples using normal CPUs, the present invention is not limited thereto. The number of symbols in sTTI, symbol duration, CPU duration and / or other parameters can be set without limitation. Although examples will be described hereinafter in which OFDM symbols are used in the downlink and SC-FDMA symbols are used in the uplink, the present invention is not limited thereto. For example, access schemes other than OFDM or SC-FDMA may be specified (configured) for sTTIs.

FIG. 3A is a diagram of a first configuration example of sTTIs. As shown in FIG. 3A, in this configuration example, sTTI consists, like nTTI, of 14 OFDM symbols (or SC-FDMA symbols), but the duration of each OFDM symbol (each SC-FDMA symbol) is shorter than the symbol duration in nTTI (= 66.7 μs).

As shown in FIG. 3A, while maintaining the number of nTTI symbols and shortening the symbol duration, the physical layer signal can be configured the same as in the nTTIs (eg, the same mapping to resource elements). In addition, while keeping the same number of characters as nTTI, it is possible to include in sTTI the same amount of information (the same number of bits) as in nTTI.

Since the symbol duration and the sub-carrier spacing are reciprocal, when shortening the symbol duration as shown in FIG. 3A, the subcarrier spacing becomes larger than the nTTI (15 kHz) subcarrier spacing. By increasing the subcarrier spacing, it is possible to effectively combat inter-channel interference caused by the Doppler shift when the user terminal moves and the degradation of communication quality due to phase noise at the receiver of the user terminal. More specifically, by increasing the subcarrier spacing, the degradation of the communication quality in the high frequency bands, for example, at several tens of gigahertz, can be effectively prevented.

FIG. ZV is a diagram of a second sTTI configuration example. As shown in FIG. 3B, according to the second configuration example, sTTI consists of fewer OFDM symbols (or SC-FDMA symbols) than nTTIs, but each OFDM symbol (each SC-FDMA symbol) has the same duration as nTTI (= 66.7 μs). In this case, the sTTI can be formed by the nTTI character elements (ie, can be formed by fewer characters). For example, an sTTI can be generated by using a portion of 14 symbols contained in one subframe. FIG. The sTTI TS consists of seven OFDM symbols (SC-FDMA symbols), i.e. half of the nTTI characters.

As shown in FIG. 3B, while maintaining the symbol duration and reducing the number of symbols, the amount of information (the number of bits) that can be accommodated in sTTI can be less than in nTTI. Accordingly, the UE can perform receiving operations (eg, demodulation, decoding, etc.) on the information contained in the sTTI in a shorter time than the nTTI, whereby processing latency can be reduced. In addition, with the same symbol duration as in existing systems, sTTI signals and nTTI signals can be frequency multiplexed in the same system bandwidth (or on the same carrier, in the same cell, on the same EN, etc. .), which makes it possible to maintain compatibility with nTTI.

For example, when using Frame Configuration Type 1 (FDD), the downlink control channel (also called sPDCCH channel, for example) and / or the downstream shared channel (also called sPDSCH channel, for example) can be transmitted using two symbols and / or one slots of sTTI intervals of existing systems.

In addition, in Frame Configuration Type 1 (FDD), an uplink control channel (also called sPUCCH, for example) and / or an uplink common channel (also called sPUSCH, for example) can be transmitted using an sTTI consisting of at least one of the following: two characters, four characters, one slot.

Alternatively, when using type 2 frame configuration (TDD), at least one of sPDCCH, sPDSCH, sPUCCH, and sPUSCH can be transmitted using single-slot sTTIs.

(Examples of configurations with abbreviated TTIs)

The following describes examples of configurations with sTTI. When using sTTI, the user terminal can be configured to work with both nTTI and sTTI, which allows maintaining compatibility with existing systems (LTE versions 8-12).

FIG. 4 shows examples of configurations with nTTI and sTTI. Note that in FIG. 4 presents only examples, which are not limiting in any way. For example, the number and positions of subframes in which sTTIs are used are not limited to those shown in FIG. 4A.

FIG. 4A is a diagram of a first example of a reduced TTI configuration. As shown in FIG. 4A, nTTIs and sTTIs may coexist in time in the same frequency domain (eg, on a single elementary carrier (EH)). More specifically, sTTI can be used in a specific subframe (or in a specific radio frame) of one EL. For example, in FIG. 4A, five consecutive subframes of one ET use sTTIs, and other subframes of the same ET use nTTIs.

These specific subframes can be subframes, which can be configured as subframes of a multicast-broadcast single-frequency network (MBSFN), or subframes that contain (or do not contain) certain signals, for example, a main block. information (English Master Information Block, MIB), synchronization signals, etc.

FIG. 4B is a diagram of a second reduced TTI configuration example. As shown in FIG. 4B, carrier aggregation (AH) or double linking (DC) can be accomplished by combining EH with nTTI and EH with sTTI. More precisely, sTTIs can be used on specific AOs (more precisely, on specific AOs in the uplink and / or in the downlink). For example, in FIG. 4B sTTIs are used on one downlink ET, and nTTIs are used on the other both downlink and uplink ETs.

In addition, when using AH, sTTIs can be used on a specific EH (PCell and / or SCell) of one radio base station. On the other hand, when using DS, sTTI can be used on specific ES (PCell and / or SCell) in the Master Cell Group (MCG) formed by the first base radio station (Master radio station, English Master eNB, MeNB), or on specific ENs (primary secondary cell (PSCell) and / or SCell) in a Secondary Cell Group (SCG) formed by a second radio base station (Secondary eNB, English Secondary eNB, SeNB)).

FIG. 4C is a diagram of a third reduced TTI configuration example. As shown in FIG. 4C, sTTI can be used on both the downlink and uplink. As an example, in FIG. 4C shows a case where nTTIs are used on the uplink TDD carrier and sTTIs are used on the downlink.

In this case, specific downlink or uplink channels or signals can be placed (configured) in the sTTI. For example, a configuration may be used in which PUCCHs are allocated to nTTIs and PUSCHs are allocated to sTTIs. In this case, the UE may transmit PUCCH in nTTIs and PUSCH in sTTIs.

(Method for determining reference resources CSI)

The following discusses how resources that can be used for CSI measurements are determined in existing LTE systems. These resources are also called CSI reference resources, reference resources, etc. Throughout this document, the term "reference CSI resources" will be used.

The frequency domain for the reference CSI resources for a predetermined serving cell is defined as a group of downlink Physical Resource Blocks (PRBs) from which CQI values related to the respective frequency bands are derived.

The time domain for the reference CSI resources for a predetermined serving cell is defined as one downlink subframe or special subframe for a predetermined number (n _{CQI_ref} ) of subframes preceding the subframe n in which the CSI is transmitted (i.e., as subframe nn _{CQI_ref} ).

When transmitting P-CSI in subframe n, n _{CQI_ref is} set to the smallest value greater than or equal to four such that subframe nn _{CQI_ref} corresponds to a valid downlink subframe or special subframe. In this case, the subframe in which the CSI is measured is the closest subframe four subframes (4 ms) or more preceding the subframe for CSI transmission and satisfying predetermined conditions. It will be appreciated that this “valid downlink subframe or special subframe” may be a subframe satisfying the conditions stipulated in the predefined specifications (eg 3GPP TS 36.213).

When receiving an uplink DCI CSI trigger (in an uplink grant) and transmitting A-CSI in subframe n, the value of n _{CQI_ref} is such that the reference CSI resource is in a valid downlink subframe or special subframe in which the CSI trigger was received ... However, in existing LTE systems, the UE transmits A-CSI based on this upstream grant through k subframes after the subframe in which the upstream grant containing the CSI trigger is received. The value of k is set depending on the frame configuration (FDD / TDD), etc .; in existing systems, k is greater than or equal to four. In other words, in this case, the value of n _{CQI_ref is} greater than or equal to four.

When receiving a CSI trigger in a random access response grant directing reception of a random access response and transmitting an A-CSI in subframe n, the n _{CQI_ref} value is four, and the n-n _{CQI_ref} subframe corresponding to a valid downlink subframe or special subframe is received after the subframe, in which the specified random access response grant was accepted.

Although other methods are known for determining the reference CSI resources, in conventional LTE terminals, the reference CSI resources are determined based on the above approaches. It should be appreciated that the eNB may restrict the group of subframes in which the CSI measurement is possible (CSI measurement restriction). In addition, the eNB may report information related to the reference CSI resources to the UE using higher layer signaling (eg, RRC signaling), physical layer signaling (eg, DCI), or a combination of the above. The information related to the reference CSI resources can be, for example, a subframe index, information about a group of subframes (eg, a bitmap), radio resource location, and so on.

Next, referring to FIG. 5 and FIG. 6 describes specific examples of the reference CSI resources. FIG. 5 is a diagram of examples of reference CSI resources for use for P-CSI transmission in existing systems. FIG. 5 shows a downlink carrier and an uplink carrier. Note that in FIG. 6-12 show the same circuit as in FIG. 5. In addition, although each of FIGS. 5-12 show two carriers for ease of explanation, configurations with downlink and uplink transmission and reception on a single carrier may be used.

FIG. 5, the UE periodically (in this example, every five subframes) transmits the P-CSI on the uplink. FIG. 5, subframes four subframes preceding each subframe for P-CSI transmission are valid subframes and contain CSI reference resources.

FIG. 6 is a diagram of examples of reference CSI resources for use for A-CSI transmission in existing systems. FIG. 6, the UE transmits an uplink A-CSI at n _{CQI_ref} subframes (four subframes in this example) after the subframe in which the uplink grant containing the CSI trigger was received.

The above described method for determining the reference CSI resources is based on the principles of existing LTE systems. Accordingly, with the introduction of sTTIs and / or a reduction in processing time, there is a risk that the use of the above-described method for determining the reference CSI resources may cause disadvantages such as, for example, a decrease in communication quality, bandwidth, spectral efficiency, etc.

Therefore, the inventors of the present invention have come to the idea of appropriately determining the reference CSI resources using sTTIs and / or reduced processing time. In accordance with one embodiment of the present invention, the CSI reference resources can be flexibly allocated and used for measurement in the UE, which can be expected to improve the overall system throughput.

Hereinafter, embodiments of the present invention will be explained in detail with reference to the accompanying drawings. It will be appreciated that the radio communication method in accordance with each embodiment can be used individually or in combination. In addition, in each embodiment, the configurations previously described with reference to FIGS may be used for sTTIs. 3, fig. 4 and / or other figures.

Despite the disclosure of the embodiments on the example of an LTE system, the present invention is not limited to this system, but is applicable to any system that uses sTTI and reduced processing time. In addition, although CSI triggers are used as examples in the following embodiments of CSI message requests, CSI measurement requests, CSI measurement report requests, and / or others may also be used.

(Radio communication method)

<First embodiment>

In the following first embodiment of the present invention, using sTTIs and / or shortening the processing time, a conventional CSI determination method is applied.

In the first embodiment, when transmitting P-CSI in subframe n, the CSI reference resource is in the nearest subframe at least four subframes prior to the subframe in which the P-CSI is transmitted and satisfying predetermined conditions. Accordingly, even when sTTIs and / or reduced processing time are used for P-CSI transmission, the same principle can be used as before.

When transmitting the A-CSI in subframe n in the first embodiment, different principles from those currently applied are possible. In the following description, it is assumed that a reduction in processing time is used, and therefore the UE, upon receiving an upward grant in a subframe, transmits N subframes after this subframe based on the indicated upward grant (N is less than four). In this case, n _{CQI_ref is} not equal to four or more, but equal to N. The CSI reference resource is, for example, in a subframe in which an upstream grant containing a CSI trigger is received.

FIG. 7 is a diagram of examples of reference CSI resources for use for A-CSI transmission in accordance with the first embodiment. In this example, N = 2. The UE measures the CSI using the CSI reference resource in the subframe in which the upstream grant containing the CSI trigger was received. Then, after n _{CQI_ref} subframes (two subframes in this example) after this subframe, the UE transmits the A-CSI on the uplink.

Next, referring to FIG. 8 describes an example of the combination of sTTIs and reduced processing time. FIG. 8 is a diagram of other examples of reference CSI resources for use for A-CSI transmission in accordance with the first embodiment. In this example, as in FIG. 7, N = 2. In addition, in this example, the UE is configured to use sTTIs (TTI = 0.5 ms) in the downlink and uplink.

The UE monitors the presence of sPDCCH in each sTTI, and upon detecting an upstream grant containing a CSI trigger, measures the CSI using the CSI reference resource in the subframe containing the sTTI in which the upstream grant was found. As shown in FIG. 8, no matter which location (which sTTI) in one subframe an upward grant is received, the UE may measure the CSI based on that one subframe.

In addition, the UE can measure the CSI both on the basis of only the sTTI in which the upward grant is received, and using resources other than the sTTI in the same subframe with which the upward grant was received as CSI reference resources. In other words, in the first embodiment, when the A-CSI transmission is initiated by the upstream grant, the CSI reference resource may be in the sTTI in which the specified upstream grant is received, or in another sTTI of the subframe in which the specified upstream grant is received.

Alternatively, the UE may know in advance that the upstream grant in which the CSI trigger is to be contained should only be received in predetermined sTTIs in one subframe. For example, the UE may know in advance that an upstream grant that is to contain a CSI trigger should only be received in the first sTTI or sTTIs contained in the first slot. This makes sequential processing possible, for example, first detecting an upward grant and then measuring CSI, thereby reducing the UE's memory and battery consumption.

When an uplink grant is detected in the sTTI contained in a subframe, after n _{CQI_ref} subframes (two subframes in this example), the UE transmits an A-CSI on the uplink. This A-CSI message can be transmitted in both sTTI (transmitted, for example, in sPUSCH) and nTTI (transmitted, for example, in PUSCH).

Note that the A-CSI message when transmitted in sTTI can only be transmitted n _{CQI_ref subframes} after the sTTI in which the upstream grant was received. In addition, the UE may control so that the relative position in the subframe of the sTTI in which the A-CSI is transmitted matches the relative position in the subframe of the sTTI in which the upward grant was received.

For example, as shown in FIG. 8, the UE may control so that upon receiving an upward grant in the first (last) sTTI of a subframe, the corresponding A-CSI is transmitted in the first (last) sTTI of a subframe following n _{CQI_ref subframes} later. It should be appreciated that such control is possible not only in the case of using sTTI in the downlink and uplink of the same duration, as shown in FIG. 8.

According to the above-described first embodiment, even when using sTTIs and / or shortening the processing time, the control timing of the P-CSI transmission can be left the same as in the existing control scheme, and the A-CSI can be transmitted earlier.

<Second embodiment>

In a second embodiment of the present invention, when using sTTIs and / or reducing processing time, the method for determining the reference CSI resources is different from the existing methods.

The second embodiment is the same as the prior art except that the time domain for the reference CSI resources is in one downlink subframe or special subframe (subframe nn _{CQI_ref} ), for a predetermined number (n _{CQI_ref} ) of subframes of the preceding subframe n in which the CSI is transmitted.

[P-CSI Transmit]

According to a second embodiment, when transmitting P-CSI in subframe n, n _{CQI_ref is} assumed to be the smallest value greater than or equal to a predetermined value (hereinafter X), where subframe n _{CQI_ref} corresponds to a valid downlink subframe or special subframe. In this document, X has a value less than four, but may have a value greater than or equal to four.

The X value used to find the CSI reference resource for the P-CSI transmission may be set in the UE using, for example, upper layer signaling (eg, RRC signaling), physical layer signaling (eg, DCI), or a combination of these techniques. In this document, information related to the X values that the UE can support is preferably communicated from the UE to the network (eg, eNB) in advance using, for example, UE capability information (UE capability). The eNB may set X for a given UE based on the specified UE capability information and / or other information (eg, UE category and / or the like).

FIG. 9 is a diagram of examples of reference CSI resources for use for P-CSI transmission in accordance with the second embodiment. In this example, the UE is set to X = 2. FIG. 9, the UE periodically (in this example, every five subframes) transmits the P-CSI on the uplink. In this example, the valid subframe is n _{CQI_ref} subframes (two subframes in this example) before the subframe in which the P-CSI is transmitted, and the UE measures the CSI using the reference CSI resource of that valid subframe.

In addition, X can be associated with sTTI durations (TTI durations) for downlink and / or uplink use. In this case, the UE may determine the value of X based on the used sTTI configuration. For example, the UE may determine the value of X based on whether shortened TTIs are provided for the uplink and / or downlink, or based on which shortened sTTIs are provided (eg, how long sTTI is provided) in the uplink and / or downlink.

These relationships between sTTI durations for downlink and / or uplink use and X values may be specified in a specification (eg, a table) or in a UE through, for example, upper layer signaling, physical layer signaling, or a combination of these methods. The above links may be set so that when sTTIs are provided in at least one of the downlink and uplink, the value of X is less than four. If nTTIs are used in both the downlink and uplink, then the above associations may be set so that the value of X is greater than or equal to four.

FIG. 10 is a diagram of other examples of reference CSI resources for use for P-CSI transmission in accordance with the second embodiment. This example is arranged so that if the P-CSI is transmitted in sTTI, then X is less than four (eg, two), and if the P-CSI is transmitted in nTTI, then X is four. In addition, in this example, information on whether the P-CSIs are transmitted in sPUCCH or normal PUCCH is set (reported) to the UE dynamically and / or semi-statically.

FIG. 10, the UE periodically (in this example, every five subframes) transmits the P-CSI on the uplink. When transmitting the P-CSI, the UE determines the value of X and n _{CQI_ref} each time based on the TTI duration used for the indicated transmission, and measures the CSI in the appropriate reference CSI resources. It should be appreciated that in the case of P-CSI transmission in sTTI (sPUCCH), P-CSIs may be transmitted in an arbitrary sTTI subframe for P-CSI transmission or in an sTTI predetermined in the specification or setting.

It should be noted that the value of X can be determined in other ways. For example, the UE may determine the value of X based on whether the use of the reduced uplink and / or downlink processing time is intended, or based on whether the use of a combination of the reduced sTTI and the reduced processing time is intended.

[A-CSI transmission]

According to the second embodiment, when transmitting A-CSI in subframe n in response to a trigger contained in an uplink grant, n _{CQI_ref is} assumed to be a predetermined value (hereinafter Y), and subframe nn _{CQI_ref} may correspond to an actual downlink subframe or special subframe. In this document, Y has a value less than four, but may have a value greater than or equal to four. The Y value may be equal to the above X value or may be different.

In addition, the subframe nn _{CQI_ref} may be a subframe in which an uplink grant is received, or it may be another subframe. In other words, the reference CSI resource may be in a subframe before and / or after a subframe in which a CSI flip-flop (upstream grant) corresponding to the A-CSI is received.

FIG. 11 is a diagram of examples of reference CSI resources for use for A-CSI transmission in accordance with the second embodiment. In this example, the CSI is measured using subframes after the subframe in which the uplink grant is received. In this example, the Y value is less than or equal to three. Upon receiving an upstream grant containing a CSI trigger, the UE finds subframe nn _{CQI_ref} based on Y.

While FIG. 11 shows an example in which sTTI is not used, even when sTTI is used, the subframe nn _{CQI_ref} can be found similarly. In addition, in FIG. 11, transmission based on the upward grant is performed four subframes after the subframe in which the upward grant was received, but this is in no way limiting.

As shown in FIG. 11, when using a configuration in which CSI RR measurements are performed after receiving an uplink grant, a long period of time may be reserved after receiving the uplink grant before transmitting data containing A-CSI, resulting in the coding burden on the UE and / or other operations, can be timed and reduced. In addition, the time from CSI measurement to CSI transmission is shortened, and the CSI measurement can be more accurate.

FIG. 12 is a diagram of other examples of reference CSI resources for use for A-CSI transmission in accordance with the second embodiment. In this example, CSI is measured in subframes preceding the subframe in which the upstream grant is received. In this example, the Y value is less than or equal to four. The UE performs CSI measurements on a sub-frame basis using implied CSI reference resources. In addition, after receiving an upstream grant containing the CSI trigger, the UE finds subframe nn _{CQI_ref} based on Y and transmits A-CSI in subframe n.

While FIG. 12 shows an example in which sTTIs are not used, even when sTTIs are used, the subframe nn _{CQI_ref} can be found similarly. In addition, in FIG. 12, transmission based on the upward grant is performed three subframes after the subframe in which the upward grant was received, but this is in no way limiting.

As shown in FIG. 12, by using the configuration in which measurements based on the reference CSI resource are performed before receiving the upward grant, it is possible to quickly respond to the upward grant with a CSI message generated using the pre-measured CSI. This configuration is preferred when the size of the CSI to be transmitted is large and / or when the data size indicated by the upstream grant is small.

It should be appreciated that at least one kind of information from information representing a positional relationship (e.g., a relative positional relationship (lead, match, lag, etc.)) between the reference CSI resource corresponding to the upstream grant containing the CSI trigger and the subframe in which this upstream grant is received, and information about whether the reference CSI resource is in the subframe in which the upstream grant containing the CSI trigger is received, and / or other types of information can be reported (set, prescribed, etc.) from an eNB at a UE using upper layer signaling (eg, RRC signaling), physical layer signaling (eg, DCI), or a combination thereof.

It should be appreciated that the method for determining the reference CSI resources, for example, described above with reference to FIG. 11 and FIG. 12 can be used even when receiving a CSI trigger in a random access response grant.

Even if neither sTTI nor processing time reduction are used, the above configuration can be used to measure CSI for A-CSI in subframes other than the subframe in which the upstream grant containing the CSI trigger is received.

According to the above-described second embodiment, the UE can adequately determine the reference CSI resources to use for P-CSI transmission and / or A-CSI transmission and control signal processing even when using sTTI and / or reducing processing time.

Note that in each of the above-described embodiment, the CSI reference resources are in subframes preceding the subframe in which the CSI is transmitted by a period that is shorter than four subframes (4ms), but the application of the present invention is not limited to this. For example, more generally, the CSI reference resources may be in subframes for a period that is shorter than a predetermined time period preceding the subframe in which the CSI is transmitted. For the specified predetermined time period, any value can be implied, for example, 3 ms, 4 ms, 5 ms, etc. In addition, as used herein, the expression “shorter than a predetermined time period” may be expressed by at least one of the following expressions: “shorter than a predetermined time period”, “equal to a predetermined time period”, and “longer than a predetermined time period”.

(Radio communication system)

The following describes the structure of a radio communication system in accordance with one embodiment of the present invention. In this radio communication system, communication is performed using one or a combination of radio communication methods in accordance with the above embodiments of the present invention.

FIG. 13 is an example of a schematic structure of a radio communication system in accordance with one embodiment of the present invention. The radio communication system 1 is configured with carrier aggregation (AH) and / or double connection (DC) for combining a plurality of frequency elementary blocks (elementary carriers) while one combining element is formed by the LTE system frequency band (for example, 20 MHz).

It should be noted that the radio communication system 1 can be called, for example, the LTE system, LTE-A, LTE-B (LTE-Beyond, extended LTE), SUPER 3G, IMT-Advanced, fourth generation mobile communication system (4G), system mobile communications of the fifth generation (5G), Future Radio Access (FRA), new radio access technology (New-RAT), or can be considered as a system for the implementation of these systems.

The radio communication system 1 contains a radio base station 11, forming a macro cell C1, and base radio stations 12a-12c, located in the macro cell C1 and forming a small cell C2 with less coverage than that of a macro cell C1. In addition, user terminals 20 are located in the macro cell C1 and in each of the small cells C2.

The user terminals 20 are configured to connect to both the radio base station 11 and the radio base stations 12. The user terminals 20 are configured to simultaneously use the macro cell C1 and small cells C2 by means of AH or DS. In addition, user terminals 20 are configured to employ AH or RS using multiple cells (elementary carriers) (eg, five AH or less, six AH or more).

Communication between user terminals 20 and the radio base station 11 may be carried out using a carrier from a relatively low frequency band (eg, 2 GHz) and a narrow bandwidth (called, eg, an existing carrier, an old type carrier, etc.). At the same time, between 20 user terminals and radio base stations

12, a carrier from a relatively high frequency range (e.g. 3.5 GHz, 5 GHz, etc.) and wide bandwidth can be used, or the same carrier as used by a radio base station can be used 11. Note that the structure of the frequency range for use in each radio base station is in no way limited to these structures.

In the radio communication system 1, a wired structure can be used (for example, means that comply with the Common Public Radio Interface (CPRI) standard, for example, with fiber optic cable, X2 interface, etc.), or a wireless connection may be established between the radio base station 11 and the radio base station 12 (or between two radio base stations 12).

The radio base station 11 and the radio base stations 12 are connected to the station 30 of the upper level, and through the station 30 of the upper level they are connected to the core network 40. It should be noted that the station 30 of the upper level can be, for example, an access gateway, a radio network controller (English Radio Network Controller). , RNC), Mobility Management Entity (MME), etc., but the possibilities are in no way limited to the above list. In addition, each radio base station 12 can be connected to the upper level station 30 via the radio base station 11.

It will be appreciated that the radio base station 11 has a relatively large coverage area and may be called a macro base station, a central node, an eNB (eNodeB), a transmitting / receiving point, etc. Radio base stations 12 have local coverage and may be referred to as small base stations, micro base stations, pico base stations, femto base stations, home eNBs (HeNB), Remote Radio Heads (RRH), transmitting / receiving points, etc. .d. Hereinafter, the radio base stations 11 and 12 are collectively referred to as the radio base stations 10, unless otherwise indicated.

User terminals 20 are configured to support various communication schemes such as LTE, LTE-A, etc., and can be both mobile communication terminals (mobile stations) and fixed communication terminals (fixed stations).

The radio system 1 uses Orthogonal Frequency Division Multiple Access (OFDMA) as the downlink radio access scheme, and the uplink uses the single carrier frequency division multiple access scheme. Single-Carrier Frequency Division Multiple Access, SC-FDMA).

OFDMA is a multi-carrier communication scheme in which communication is performed by dividing a bandwidth into multiple narrower frequency bands (subcarriers) and mapping data to each subcarrier. SC-FDMA is a single carrier communication scheme that reduces mutual interference between terminals by dividing the system bandwidth between all terminals into frequency bands formed by one or more contiguous resource blocks and allowing each of the multiple terminals to use its own bandwidth. The uplink and downlink radio access schemes are not limited to the above combination, and other radio access schemes may be used.

In the radio communication system 1, the downlinks are the downlink shared channel (PDSCH: Physical Downlink Shared CHannel) shared by all user terminals 20, the broadcast channel (PBCH: Physical Broadcast CHannel), the downlinks L1 / L2 control, etc. The PDSCH carries user data, higher-level control information and System Information Blocks (SIB). In addition, a Master Information Block (MIB) is transmitted in the Strategic Missile Forces channel.

L1 / L2 downlink control channels include the Physical Downlink Control CHannel (PDCCH), the Enhanced Physical Downlink Control CHannel (EPDCCH), the Physical Downlink Control Channel (EPDCCH), and the Physical Downlink Control Channel (EPDCCH). Control Format Indicator CHannel, PCFICH), Physical Hybrid-ARQ Indicator CHannel (PHICH), etc. Downlink Control Information (DCI) containing PDSCH and PUSCH scheduling information is transmitted via the PDCCH. The number of OFDM symbols to be used for the PDCCH is reported by the PCFICH. Delivery confirmation information (also called, for example, retransmission control information, HARQ-ACK signals, ACK / NACK signals, etc.) of the Hybrid Automatic Repeat reQuest (HARQ) in response to the PUSCH is transmitted by PHICH. EPDCCH is frequency division multiplexed with PDSCH (Downlink Shared Data Channel) and, like PDCCH, is used for DCI transmission, etc.

The radio system 1 uses a Physical Uplink Shared CHannel (PUSCH) shared by all user terminals 20 as uplinks, a Physical Uplink Control CHannel (PUCCH), a physical random access channel (English Physical Random Access CHannel, PRACH), etc. User data and higher layer control information are transmitted by the PUSCH. In addition, downlink radio quality information (CQI (Channel Quality Indicator)), delivery confirmation information, and so on are transmitted via the PUCCH. The PRACH signals random access preambles to establish connections with cells.

In the radio communication system 1, cell-specific reference signals (CRS), channel state information-reference signals (CSI-RS), reference signals are transmitted as downlink reference signals Demodulation Reference Signal (DMRS), Positioning Reference Signal (PRS), etc. In addition, in the radio communication system 1, reference measurement signals (Sounding Reference Signal, SRS), Demodulation Reference Signal (DMRS), etc. are transmitted as upstream reference signals. It will be appreciated that DMRS signals may be referred to as user terminal specific reference signals (UE specific reference signals). In this case, the reference signals to be transmitted are in no way limited to the above list. (Radio base station)

FIG. 14 is an example of a generalized structure of a radio base station in accordance with one embodiment of the present invention. The radio base station 10 includes a plurality of transmit / receive antennas 101, amplification sections 102, transmission / reception sections 103, a baseband signal processing section 104, a call processing section 105, and a communication path interface 106. It will be appreciated that one or more transmit / receive antennas 101, gain sections 102, and transmit / receive sections 103 may be provided.

User data to be transmitted from the radio base station 10 to the downlink user terminal 20 is supplied from the upper station 30 to the baseband signal processing section 104 via the communication path interface 106.

In the baseband signal processing section 104, user data is subjected to Packet Data Convergence Protocol (PDCP) layer operations, splitting and combining, transmission operations of the Radio Link Control (RLC) layer, for example, control RLC re-transmission, Medium Access Control (MAC) re-transmission control (for example, transmission operations in Hybrid Automatic Repeat reQuest (HARQ)), scheduling, transport format selection, channel coding, inverse fast Fourier transform (IFFT) operations, and precoding operations, and the result is transmitted to each transmission / reception section 103. The downlink control signals are also subjected to transmission preparation operations such as channel coding and inverse fast Fourier transform, and are transmitted to each transmission / reception section 103.

Precoded baseband signals transmitted from the baseband signal processing section 104 individually for each antenna are converted into the radio frequency range in the transmit / receive sections 103 and then transmitted. The RF signals that have passed the frequency conversion in the transmit / receive sections 103 are amplified in the amplifying sections 102 and radiated into the air from the transmit / receive antennas 101. The transmit / receive sections 103 can be formed by transmitters / receivers, transmitting / receiving circuits, or transmitting / receiving devices. , which can be described based on basic knowledge in the field of technology to which the present invention relates. It will be appreciated that the transmission / reception section 103 may be configured as a single transmission / reception section, or may include a transmission section and a reception section.

As for the uplink signals, each of the RF signals received at the transmit / receive antennas 101 is amplified in the amplification sections 102. Sections 103 transmit / receive receive uplink signals amplified in sections 102 amplification. The received signals are converted into a baseband signal by frequency conversion in the transmit / receive sections 103, and are transmitted to the baseband signal processing section 104.

In baseband signal processing section 104, user data contained in the received uplink signals is subjected to a fast Fourier transform (FFT) operation, an inverse discrete Fourier transform (IDFT) operation, error correction decoding, a reception operation in MAC layer retransmission control, reception operations the RLC layer and the PDCP layer and are transmitted to the upper layer station 30 via the communication path interface 106. The call processing section 105 performs call processing such as establishing and releasing communication channels, managing the state of the radio base station 10 and radio frequency resources.

The communication path interface 106 transmits signals to the upper station 30 and receives signals from the upper station 30 via a predetermined interface. In addition, the communication path interface 106 is configured to transmit and / or receive signals (backhaul signaling) of other radio base stations 10 via an inter-office interface (for example, an interface in accordance with the CPRI standard (Common Public Radio Interface), which can be a fiber optic cable, an X2 interface, etc.).

Sections 103 transmission / reception transmit to the user terminal 20 channels PDSCH, sPDSCH, etc. The transmit / receive sections 103 receive PUCCH, sPUCCH, etc., from the user terminal 20.

In addition, the transmit / receive sections 103 may transmit to the user terminal 20 information related to the reference CSI resources, information related to X and / or Y values that are used to indicate the reference CSI resources, and information on the positional relationship between the reference CSI resource. corresponding to the upstream grant containing the CSI trigger and the subframe in which the upstream grant is transmitted and / or other pieces of information.

FIG. 15 is a diagram of an example of a functional structure of a radio base station in accordance with one embodiment of the present invention. It will be appreciated that, in addition to the functional blocks shown pertaining to the parts important for this embodiment, the radio base station 10 also contains other functional blocks that are also necessary for radio communication.

The baseband signal processing section 104 includes a control section (scheduler) 301, a transmission signal generating section 302, a display section 303, a received signal processing section 304, and a measurement section 305. It will be appreciated that these functional blocks must be contained in the radio base station 10, but some or all of these functional blocks may not be contained in the baseband signal processing section 104.

The control section 301 (scheduler) controls the radio base station 10 as a whole. The control section 301 may be constituted by a controller, a driving circuit, or a control device, which may be described based on basic knowledge in the art to which the present invention pertains.

The control section 301, for example, controls the signal generation by the transmission signal generation section 302, the distribution of the signals by the display section 303, and so on. In addition, the control section 301 controls operations of receiving a signal in the received signal processing section 304, measuring signals in the measuring section 305, and so on.

Control section 301 controls scheduling (eg, resource allocation) of downlink data signals transmitted on the PDSCH and downlink control signals transmitted on the PDCCH and / or EPDCCH. The control section 301 controls generation of uplink control signals (eg, delivery confirmation information, etc.) and uplink data signals based on the decision to control retransmission for downlink data signals, and so on. In addition, the control section 301 controls the scheduling of downlink reference signals, for example, synchronization signals (for example, the main synchronization signal PSS / secondary synchronization signal SSS), CRS, CSI-RS, DM-RS, etc.

In addition, control section 301 controls the scheduling of uplink data signals transmitted on the PUSCH, uplink control signals transmitted on the PUCCH and / or PUSCH (e.g., delivery acknowledgment information), random access preambles transmitted on the PRACH, uplink reference signals etc.

Upon receiving the UCI received from the user terminal 20 by the received signal processing section 304, the control section 301, based on the UCI, performs retransmission control and scheduling control in the user terminal 20. For example, upon receiving the HARQ-ACK from the received signal processing section 304, the control section 301 checks whether it is necessary to retransmit to the user terminal 20, and controls so that retransmission is performed if it is required to retransmit.

Control section 301 may control to communicate in cells (per EN) using sTTIs with TTIs of less than 1 ms (subframes in existing LTE systems), or to communicate in cells where communication is controlled using reduced processing time, shorter than existing LTE systems. For example, control section 301 may configure user terminal 20 to communicate using sTTIs and / or reduced processing time.

In addition, control section 301 controls user terminal 20 so that CSI measurement is performed using reference CSI resources in at least one of these cells. For example, control section 301 transmits signals for CSI measurement, such as CRS, CSI-RS, and / or etc., in the CSI reference resources. In addition, control section 301 performs control to receive the measured CSI in a predetermined subframe (subframe and / or sTTI).

It should be appreciated that the above reference CSI resource is in a subframe earlier than the predetermined subframe in which the CSI is transmitted by a period that is shorter than the predetermined time period (eg, 4 ms). For example, this reference CSI resource may be in a subframe in which the CSI flip-flop is transmitted, located before a predetermined subframe in which the CSI is transmitted, for a period that is shorter than a predetermined time period, or in a subframe other than the subframe in which the flip-flop is transmitted. CSI.

The transmission signal generating section 302 generates downlink signals (downlink control signals, downlink data signals, downlink reference signals, etc.) based on the commands from the control section 301, and transmits these signals to the display section 303. The transmission signal shaping section 302 may be constituted by a signal generator, a shaping circuit, or a shaping device, which may be described based on basic knowledge in the art to which the present invention pertains.

For example, based on the commands from the control section 301, the transmit signal generating section 302 generates downlink assignments reporting information about the distribution of the downstream signal and upstream grants reporting information about the distribution of the upward signal. In addition, the downlink data signals undergo an encoding operation and a modulation operation, and so on. using coding ratios and modulation schemes determined based on channel state information (CSI) from each user terminal 20.

The mapping section 303 maps the downlink signals generated in the transmission signal generating section 302 to predetermined radio resources based on commands from the control section 301, and transmits the obtained signals to the transmission / reception section 103. The display section 303 may be constituted by a display, a display circuit, or a display device, which may be described based on basic knowledge in the art to which the present invention pertains.

The received signal processing section 304 performs reception operations (eg, de-mapping, demodulation, decoding, etc.) on the signals received from the transmission / reception sections 103. In this case, the received signals include, for example, uplink signals transmitted from the user terminals 20 (uplink control signals, uplink data signals, uplink reference signals, etc.). For the received signal processing section 304, a signal processor, signal processing circuitry, or signal processing apparatus may be used and may be described based on basic knowledge in the art to which the present invention pertains.

The received signal processing section 304 transmits the decoded information obtained by the receiving operations to the control section 301.

For example, when receiving the PUCCH channel containing the HARQ-ACK signal, the received signal processing section 304 transmits the HARQ-ACK signal to the control section 301. In addition, the received signal processing section 304 transmits received signals, signals after receiving operations, and so on. to section 305 measurements.

Measurement section 305 performs measurements with respect to the received signals. The measurement section 305 may be constituted by a meter, a metering circuit, or a metering device, which may be described based on basic knowledge in the art to which the present invention pertains.

When receiving signals, the measurement section 305 may measure, for example, the power of the received signal (for example, the power of the received reference signal (Reference Signal Received Power, RSRP), the quality of the received signal (for example, the quality of the received reference signal (Reference Signal Received Quality, RSRQ), Signal to Interference plus Noise Ratio (SINR) and / or the like), channel conditions, etc. Measurement results can be transmitted to control section 301.

(User terminal)

FIG. 16 is an example of the general structure of a user terminal in accordance with one embodiment of the present invention. User terminal 20 includes a plurality of transmit / receive antennas 201, gain sections 202, transmit / receive sections 203, baseband signal processing section 204, and an application section 205. It should be appreciated that one or more transmit / receive antennas 201, gain sections 202 may be provided. and sections 203 transmission / reception.

RF signals received at transmit / receive antennas 201 are amplified in gain sections 202. Sections 203 transmit / receive receive downlink signals amplified in sections 202 amplification. In the transmit / receive sections 203, the received signals are subjected to frequency conversion and converted into a baseband signal, and then passed to the baseband signal processing section 204. Sections 203 transmit / receive may be formed by transmitters / receivers, transmit / receive circuits, or transmit / receive devices, which can be described based on the basic knowledge in the field of technology to which the present invention relates. It will be appreciated that the transmit / receive section 203 may be configured as a single transmit / receive section, or may comprise a transmitting section and a receiving section.

In the baseband signal processing section 204, the received baseband signal is subjected to an FFT operation, error correction decoding, a reception operation in retransmission control, and so on. The downstream user data is transmitted to the application section 205. The application section 205 performs operations related to the layers above the physical layer, the MAC layer, and so on. In addition, broadcast information from the downlink data is transmitted to the application section 205.

At the same time, upstream user data is transmitted from the application section 205 to the baseband signal processing section 204. The baseband signal processing section 204 performs a transmission operation in retransmission control (for example, an HARQ transmission operation), channel coding, precoding, a discrete Fourier transform (DFT) operation, an IFFT operation, etc., and the result is passed to the transmission section 203. / reception. The baseband signals transmitted from the baseband signal processing section 204 are converted into the radio frequency range in the transmit / receive sections 203 and transmitted. RF signals that have passed the frequency conversion in the transmit / receive sections 203 are amplified in the amplifying sections 202 and radiated into the air from the transmit / receive antennas 201.

Sections 203 transmit / receive receive channels PDSCH, sPDSCH, etc. from the radio base station 10. The transmit / receive sections 203 transmit PUCCH, sPUCCH, etc., to the radio base station 10.

In addition, the transmit / receive sections 203 may transmit, from the radio base station 10, information related to the reference CSI resources, information related to X and / or Y values that are used to indicate the reference CSI resources, and information on the positional relationship between the reference CSI resource. corresponding to the upstream grant containing the CSI trigger and the subframe in which the upstream grant is transmitted and / or other pieces of information.

FIG. 17 is an example of a functional structure of a user terminal in accordance with one embodiment of the present invention. It will be appreciated that, in addition to the functional blocks shown pertaining to the elements important for this embodiment, the user terminal 20 also contains other functional blocks that are also necessary for radio communication.

The baseband signal processing section 204 provided in the user terminal 20 includes a control section 401, a transmission signal generating section 402, a display section 403, a received signal processing section 404, and a measurement section 405. It should be appreciated that these functional blocks must be contained in the user terminal 20, but some or all of these functional blocks may not be contained in the baseband signal processing section 204.

The control section 401 controls the user terminal 20 as a whole. For the control section 401, a controller, a driving circuit, or a control device may be used, which may be described based on basic knowledge in the field of the present invention.

The control section 401, for example, controls the generation of signals in the transmission signal generation section 402, the distribution of signals by the display section 403, and so on. In addition, the control section 401 controls operations of receiving a signal in the received signal processing section 404, measuring signals in the measuring section 405, and so on.

The control section 401 receives downlink control signals (signals transmitted on the PDCCH / EPDCCH) and downlink data signals (signals transmitted on the PDSCH) transmitted from the radio base station 10 through the received signal processing section 404. The control section 401 controls the generation of uplink control signals (e.g., delivery confirmation information, etc.) and / or uplink data signals based on the results of deciding whether to control retransmission for downlink control signals and / or downlink data signals, etc. ...

The control section 401 may control such that communication occurs in cells (per EN) using sTTIs with a TTI of less than 1 ms (subframes in existing systems), or so that communication occurs in cells where communication is controlled using a reduced processing time shorter than existing LTE systems. The control section 401 controls the measurement section 405 and / or other functional blocks so that in at least one of these cells, the CSI measurement is performed based on the reference CSI resources. In addition, the control section 401 performs control so that the measured CSI is transmitted in a predetermined subframe (subframe and / or sTTI).

It should be appreciated that the specified reference CSI resource is in a subframe earlier than the predetermined subframe in which the CSI is transmitted by a period that is shorter than the predetermined time period (eg, 4 ms). For example, this reference CSI resource may be in a subframe in which a CSI flip-flop is received prior to a predetermined subframe in which the CSI is transmitted, for a period that is shorter than a predetermined time period, or in a subframe other than the subframe in which the flip-flop is received. CSI.

In addition, the control section 401 may control the measurement section 405 to set the specified period to be shorter than the predetermined time period. For example, if transmission section 203 transmits CSI periodically, control section 401 may control measurement section 405 to set the specified period to be shorter than a predetermined time period based on a predetermined value that is adjusted or based on whether reduced Uplink and / or downlink TTI.

In addition, when various pieces of information transmitted from the radio base station 10 are received from the received signal processing section 404, the control section 401 may adjust the parameters used for the specified control based on the specified information.

The transmission signal generating section 402 generates upstream signals (upstream control signals, upstream data signals, upstream reference signals, etc.) based on the commands from the control section 401 and transmits these signals to the display section 403. The transmission signal shaping section 402 may be constituted by a signal generator, a shaping circuit, or a shaping device, which may be described based on basic knowledge in the art to which the present invention pertains.

For example, transmission signal generating section 402 generates uplink control signals related to delivery confirmation information, channel state information (CSI), and so on based on commands from control section 401. In addition, based on the commands from the control section 401, the transmission signal generating section 402 generates uplink data signals. For example, if an upward grant is contained in the downlink control signal transmitted from the radio base station 10, the control section 401 instructs the transmission signal generation section 402 to generate an uplink data signal.

The display section 403 maps the downlink signals generated in the transmission signal generating section 402 to radio resources based on commands from the control section 401, and transmits the received signals to the transmission / reception section 203. The display section 403 may be constituted by a display, a display circuit, or a display device, which can be described based on the basic knowledge of the art to which the present invention pertains.

The received signal processing section 404 performs reception operations (eg, de-mapping, demodulation, decoding, etc.) on the signals received from the transmission / reception sections 203. The received signals include, for example, downlink signals (downlink control signals, downlink data signals, downlink reference signals, etc.) transmitted from the radio base station 10. The received signal processing section 404 may be formed by a signal processor, a processing circuit signal or signal processing device, which can be described based on basic knowledge in the field of technology to which the present invention relates. In addition, the received signal processing section 404 may form a receiving section in accordance with the present invention.

The received signal processing section 404 transmits the decoded information obtained by the receiving operations to the control section 401. The received signal processing section 404 transmits to the control section 401, for example, broadcast information, system information, RRC signaling, DCI, etc. In addition, the received signal processing section 404 transmits received signals, signals after receiving operations, and so on. to section 405 measurements.

Measurement section 405 performs measurements with respect to the received signals. For example, measurement section 405 performs measurements using CRS, CSI-RS and / or others transmitted from the radio base station 10. For example, section

The measurement 405 is configured to determine the TTIs, sTTIs, and / or the like that contain the reference CSI resources and measure the CSI using these reference CSI resources. Measurement section 405 may be constituted by a meter, measurement circuit, or metering device, which may be described based on basic knowledge in the art to which the present invention pertains.

Measurement section 405 may measure, for example, received power (eg, RSRP), reception quality (eg, RSRQ), channel states, etc. received signals. The measurement results can be transmitted to the control section 401.

(Hardware structure)

In the functional diagrams used to describe the above embodiments, blocks are shown in functional modules. These functional blocks (components) can be implemented with arbitrary combinations of hardware and software. However, the means for realizing each functional block are not specifically limited. In other words, each functional block can be implemented by one physically and / or logically integral part of the device, or it can be implemented by direct and / or indirect connection of two or more physically and / or logically separated parts of the device (through, for example, a wired or wireless connection ) and the use of this many parts of the device.

The above means that the radio base station, user terminal, etc. in accordance with embodiments of the present invention, may function as a computer performing operations of the radio communication method of the present invention. FIG. 18 is a diagram of an example hardware structure of a radio base station and user terminal in accordance with one embodiment of the present invention. The above-described radio base stations 10 and user terminals 20 may be implemented as a computing device including a processor 1001, a memory 1002, a memory 1003, a communication device 1004, an input device 1005, an output device 1006, and a bus 1007.

It should be noted that in the following description, the word "device" can be replaced by the word "circuit", "module", etc. The hardware structure of the radio base station 10 and user terminal 20 may contain one or more instances of each of the devices shown in the drawings, or may not contain some of these devices.

For example, although only one processor 1001 is shown, multiple processors may be provided. In addition, operations can be performed on a single processor or on two or more processors sequentially or in other ways. It should be appreciated that the processor 1001 may be implemented by one or more integrated circuits.

Each functional module of the radio base station 10 and user terminal 20 is implemented by reading predetermined software (program) into hardware, such as processor 1001 or memory 1002, and by allowing processor 1001 to perform computations, communication device 1004 to communicate, memory 1002 and memory 1003 to read and / or write data.

The processor 1001 can control an entire computer by, for example, executing an operating system. The processor 1001 can be configured using a central processing unit (CPU) including interfaces to a peripheral device, a controller, a computing device, a recorder, and so on. For example, the above-described baseband signal processing section 104 (204), call processing section 105, etc. can be implemented by processor 1001.

The processor 1001 reads programs (program codes), program modules or data from the memory 1003 and / or communication device 1004 into the memory 1002 and performs various operations in accordance therewith. With regard to these programs, programs can be used that enable the computer to perform at least part of the operations of the above-described embodiments of the invention. For example, the control section 401 of the user terminals 20 may be implemented by control programs stored in the memory 1002 and executed by the processor 1001; other functional blocks can be implemented similarly.

Memory 1002 is a computer-readable recordable medium and can be formed, for example, by at least one of the following devices: read only memory (ROM), erasable and programmable read only memory (EPROM), electrically erasable and programmable read only memory (EEPROM) , random access memory (RAM) and / or other suitable media for storing information. Memory 1002 may be referred to as a register, cache, main memory (main storage), etc. The memory 1002 is configured to store executable programs (program codes), program modules, and the like. to implement radio communication methods in accordance with embodiments of the present invention.

The storage device 1003 is a computer-readable recordable medium and can be formed, for example, by at least one device from a floppy disk, a floppy disk (registered trademark floppy disk), a magneto-optical disk (for example, a compact disk (English Compact Disc ROM, CD- ROM), etc.), Digital Versatile Disc, Blu-ray Disc (registered trademark), removable disk, hard disk, smart card, flash memory device (such as card memory, removable storage, removable disk, etc.), magnetic stripe, database, server and / or other suitable storage medium. The storage device 1003 may be referred to as an auxiliary storage device.

Communication device 1004 is hardware (transmitter / receiver) for intercomputer communication using wired and / or wireless networks, and may be called, for example, a network device, network controller, network card, communication module, etc. Communication device 1004 can be configured to contain a high frequency switch, antenna switch, filter, frequency synthesizer, and so on. for the purpose of realizing, for example, frequency division duplex (FDD) and / or time division duplex (TDD). For example, the above-described transmit / receive antennas 101 (201), amplification sections 102 (202), transmit / receive sections 103 (203), communication path interface 106, etc. may be implemented by means of the communication device 1004.

Input device 1005 is a device (eg, keyboard, mouse, microphone, switch, button, sensor, etc.) for receiving information from the outside. Output device 1006 is an output device (eg, display, acoustic emitter, LED, etc.) for outputting information. It will be appreciated that the input device 1005 and the output device 1006 may be combined into a single structure (eg, a touch panel).

Devices of these types, including processor 1001, memory 1002, and others, are connected by bus 1007 to exchange information. Bus 1007 can be formed by a single bus, or can be formed by buses that are different for different parts of the device.

The design of the radio base station 10 and user terminal 20 may include hardware such as an Application-Specific Integrated Circuit (ASIC), a Programmable Logic Device (PLD), a programmable array of logic elements. . Field Programmable Gate Array, FPGA), etc., and all or part of the functional blocks may be implemented by the specified hardware. For example, processor 1001 can be implemented with at least one of these hardware.

(Modifications)

It should be appreciated that the terms used in this disclosure, and the terms necessary to understand this disclosure, may be replaced by other terms that have the same or similar meaning. For example, the terms "channels" and / or "symbols" can be replaced by the term "signals" (or "signaling"). "Signals" can be "messages". The reference signal may be abbreviated "OC" and may be called pilot, pilot, and so on. depending on the applicable standard. An elementary carrier (EH) can be called a cell, a frequency carrier, a carrier frequency, etc.

A radio frame can contain one or more periods (frames) in the time domain. Each of one or more periods (frames) constituting a radio frame may be referred to as a subframe. A subframe can contain one or more slots in the time domain. In addition, a slot in the time domain may be composed of one or more symbols (OFDM symbols, SC-FDMA symbols, etc.).

A radio frame, subframe, slot, and symbol are temporary units in signaling operations. The radio frame, subframe, slot, and symbol may be referred to by other suitable names. For example, one subframe, a group of consecutive subframes, or one slot may be referred to as a transmission time interval (TTI). Thus, the subframe and TTI can be a subframe (1 ms) in existing LTE, or can be a period shorter than 1 ms (eg, 1-13 symbols) or a period longer than 1 ms.

In this document, TTI denotes, for example, the smallest scheduling time unit in a radio communication. For example, in LTE systems, the radio base station schedules the allocation of radio frequency resources (eg, frequency bands and transmit power values allowed for use by each user terminal) for each user terminal in TTI units. The definition of TTI is not limited to the above definition. The TTI can be an elementary unit of time in the transmission of channel-coded data packets (transport blocks), or it can be a processing element in scheduling, link adaptation, etc.

A TTI with a time duration of 1 ms may be called a regular TTI (TTI in LTE versions 8-12), a long TTI, a regular subframe, a long subframe, and so on. A TTI that is shorter than the normal TTI may be called a shortened TTI, a short TTI, a shortened subframe, a short subframe, and the like.

A resource block (RB), which is a resource allocation unit in the time domain and in the frequency domain, may contain one subcarrier or multiple subcarriers contiguous in the frequency domain. In the time domain, a resource block can contain one symbol or multiple symbols and can be as long as one slot, one subframe, or one TTI. One TTI and one subframe may contain one or multiple resource blocks. RB can be called a physical resource block (English Physical RB, PRB), a pair of PRBs, a pair of resource blocks, etc.

A resource block can be configured from one resource element (ER) or from a plurality of resource elements. One ER can be, for example, a radio resource area formed by one subcarrier and one symbol.

It should be appreciated that the above-described structures of radio frames, subframes, slots, symbols, etc. are just examples. For example, the number of subframes contained in a radio frame, the number of slots contained in a subframe, the number of symbols and resource blocks contained in a slot, the number of subcarriers contained in a resource block, the number of symbols in the TTI, the symbol duration, the length of the cyclic prefix (CPU) can be varied. change according to need.

The information and parameters described in this disclosure may be represented by absolute values or relative values with respect to a predetermined value, or may be represented in other information formats. For example, radio resources can be indicated by predetermined indices. In addition, formulas using these parameters, etc., other than those explicitly disclosed herein, may be used.

Names used for parameters, etc. in this document are not limiting in any way. For example, since the channels (physical uplink control channel PUCCH, physical downlink control channel PDCCH, etc.) and information items can be named with any suitable names, the various names assigned to these individual channels and information items are not limiting in any way.

Information, signals, and / or other entities described in this disclosure may be represented using a variety of different methods. For example, data, instructions, commands, information, signals, bits, symbols, and code sequences (chips) that may occur in this disclosure may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or photons, or any combination of the above.

Information, signals, etc. can be transmitted from higher layers to lower layers and / or from lower layers to higher layers. Information, signals, etc. can be transmitted and received through many network nodes.

Received and transmitted information, signals, etc. can be stored in a specific location (for example, in memory), or can be stored using a control table. Information, signals, etc. to be received and / or transmitted can be rewritten, updated or supplemented. Transmitted information, signals, etc. can be removed. Received information, signals, etc. can be transferred to other parts of the device.

The communication of information is in no way limited to the examples / embodiments described in the present disclosure, and other methods may be used. For example, the information message can be performed by using physical layer signaling (e.g., downlink control information (DCI), uplink control information (UCI)), higher layer signaling (e.g., radio resource control (RRC) layer signaling, broadcast information (main block) information (MIB), system information blocks (SIB), etc.), signaling of the medium access layer (MAC), other signals or combinations of these methods.

The physical layer signaling may be called L1 / L2 control information (L1 / L2 control signals) (Layer 1 / Layer 2, Layer 1 / Layer 2), L1 control information (L1 control signal), and so on. The RRC layer signaling may be referred to as RRC messages, and the signaling may be, for example, an RRC connection setup message, an RRC connection re-configuration message, and so on. MAC layer signaling can be transmitted using, for example, MAC control elements (MAC CE).

A message of predetermined information (for example, the message that "X does not change") does not have to be transmitted explicitly, but can be transmitted implicitly (by, for example, not reporting this piece of information).

Decisions can be made based on values represented by one bit (0 or 1), Boolean values representing true or false, or based on a comparison of numeric values (eg, comparison with a predetermined value).

Software, whether called program, internal program, middleware, microcode, hardware description language, or otherwise, must be understood broadly to encompass instructions, instruction sets, code, code segments, program codes, programs, subroutines, program modules, applications, software applications, software packages, objects, executable files, threads of execution, procedures, functions, etc.

Programs, commands, information, etc. can be transmitted and received through communications. For example, if the program is transmitted from a website, server, or other remote sources using wired technologies (coaxial cables, fiber optic cables, twisted pair cables and digital subscriber lines (English Digital Subscriber Line, DSL), etc. .) and / or wireless technologies (infrared radiation, microwaves, etc.), then these wired technologies and / or wireless technologies are also included in the concept of communication means.

The terms "system" and "network" as used herein are used interchangeably.

In this document, the terms "base station (BS)", "radio base station", "eNB", "cell", "sector", "group of cells", "carrier", and "elementary carrier" can be used in the same sense. A base station may be called a fixed station, a NodeB, an eNodeB (eNB), an access point, a transmitting point, a receiving point, a femto cell, a small cell, and so on.

A base station can serve one or more (eg, three) cells (also called sectors). When a base station serves multiple cells, the entire coverage area of that base station can be partitioned into many smaller areas, in each of which communication services can be provided by subsystems of the base station, for example, small indoor base stations (Remote Radio Heads). ). The term "cell" or "sector" refers to part or all of the coverage area of a base station and / or a base station subsystem providing communication services in that coverage area.

As used herein, the terms mobile station (MS), user terminal, user equipment (UE), and terminal may be used interchangeably. A base station may be called a fixed station, a NodeB, an eNodeB (eNB), an access point, a transmitting point, a receiving point, a femto cell, a small cell, and so on.

A person skilled in the art may call a mobile station a subscriber station, mobile unit, subscriber unit, wireless module, remote module, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, telephone handset, user agent, mobile client, client, or some other appropriate name.

In the present disclosure, the phrase "radio base station" can be interpreted as "user terminal". For example, each aspect / embodiment of the present invention may, instead of a configuration in which communication is carried out between a radio base station and a user terminal, be applied to a configuration in which communication is performed between a plurality of user terminals (device-to-device communication; English Device-to-Device, D2D)). In this case, the user terminal 20 may comprise functional modules of the above-described radio base stations 10. In addition, the expressions “upstream”, “downstream” and the like can be interpreted as “related to the communication side”. For example, an uplink can be understood to be a side channel.

Similarly, in the present disclosure, the phrase "user terminal" can be interpreted as "radio base station". In this case, the radio base station 10 may comprise functional modules of the above-described user terminal 20.

Some of the actions described in this document as being performed by a base station may in some cases be performed by older nodes. Obviously, in a network consisting of one or more network nodes with base stations, various operations performed to communicate with terminals can be performed by base stations, one or more network nodes other than base stations (for example, MME nodes (eng. Mobility Management Entity, mobility management node), S-GW nodes (Serving-Gateway, etc.) or combinations of these nodes.

The aspects / embodiments illustrated in the present disclosure may be used singly or in combination with each other and may vary depending on the embodiment. The order of operations, sequences, flowcharts, etc., used in this document to describe aspects / embodiments, may be changed, as long as this does not lead to conflict. For example, although in the present disclosure the various methods are illustrated by different components of the steps following in the exemplary order, the specific order illustrated herein is in no way limiting.

The examples / embodiments illustrated herein can be applied to LTE, LTE-A, LTE-B, SUPER 3G, IMT-Advanced, 4G, 5G, FRA, New RAT, New Radio (NR) systems , New radio access (NX) systems, Future generation radio access (FX) systems of the Global System for Mobile communications (GSM (registered trademark)), CDMA2000 , for Ultra Mobile Broadband (UMB) systems, for IEEE 802.11 (Wi-Fi (registered trade mark)), IEEE 802.16 (Wi-MAX (registered trade mark)), IEEE 802.20, for communication systems over short distances using Ultra-Wide Band (UWB) signals, for Bluetooth (registered trademark) and for systems using other suitable radio communication methods and / or systems after the next generations, improved on the basis of these systems.

The expression “based on” as used in this disclosure does not mean “based on alone” unless explicitly stated. In other words, the expression “based on” means both “based on” and “based on at least”.

An indication of elements by designations such as "first", "second", etc. in this document, as a rule, does not limit the number / number or order of these elements. These symbols are used for convenience only, as a way to distinguish between two or more elements. Thus, the mention of the first and second elements does not mean that only two elements can be used, or that the first element must somehow precede the second element.

The terms “decide” and “determine” in this document encompass a wide variety of actions. For example, the terms "decide" and "determine" in this document can be interpreted to mean making decisions and performing checks related to the calculation, calculation, processing, output, research, retrieval (for example, lookup in a table, database or any other data structure), fact-finding, etc. In addition, the terms "decide" and "determine" in this document can be interpreted to mean making decisions and conducting checks related to the reception (for example, the reception of information), transmission (for example, the transmission of information), input, output, access (for example, accessing data in memory), etc. In addition, the terms "decide" and "determine" in this document can be interpreted to mean making decisions and performing checks related to disambiguation, selection, selection, determination, comparison, etc. In other words, the terms "decide" and "determine" in this document can be interpreted to mean making decisions and conducting checks associated with an action.

In this document, the terms "connected", "connected" and any of their variations mean all direct or indirect connections or connections between two or more elements, allowing the presence of one or more intermediate elements between two elements that are "connected" or "connected" to each other ... A link or connection between elements can be physical, logical, or a combination of these types of links or connections. For example, “connection” can be interpreted as “access”. In the sense used in this document, two elements can be considered connected or connected to each other using one or more electrical conductors, cables and / or printed electrical connections, and, as a few non-limiting and non-exclusive examples, using electromagnetic energy, such as electromagnetic energy having wavelengths in the radio frequency, microwave and optical (both visible and invisible) ranges.

When, for example, terms such as “include”, “comprise” and their variations are used herein or in the claims, these terms are to be understood in an inclusive sense similar to that in which the term “cover” is used. The conjunction “or” in this document and in the claims should not be construed as meaning excluding disjunction.

Now, despite the detailed disclosure of the present invention above, it should be apparent to a person skilled in the art that the present invention is in no way limited to the embodiments described herein. The present invention can be carried out with various changes and in various modifications without departing from the essence and scope of the present invention defined by the claims. Accordingly, the disclosure herein is provided for the purpose of illustrating examples only and should in no way be construed as limiting the present invention.

Japanese Patent Application No. 2016-146464, filed July 26, 2016, including the specification, drawings, and abstract, is hereby incorporated by reference in its entirety.

Claims (23)

1. Terminal containing: a transmission section, configured to transmit to the base station information about the technical capabilities of the terminal related to the value (X) used to find the reference resource of the channel status information (CSI); a receiving section configured to receive information related to X from the base station; and a control section configured to measure channel state information (CSI) on the basis of the reference resource of the channel state information (CSI) in slot nn _CQI _ _ref, where n corresponds to the slot in which the reported channel state information (CSI), an _CQI _ _ref matches the smallest value greater than or equal to X as indicated by information related to X; wherein the transmitting section is further configured to transmit channel state information (CSI) in a slot in which channel state information (CSI) is reported. 2. A radio communication method for a terminal, in which: transmitting to the base station information about the technical capabilities of the terminal related to the value (X) used to find the reference resource of the channel state information (CSI); receive information related to X from the base station; and measured channel state information (CSI) on the basis of the reference resource of the channel state information (CSI) in slot nn _CQI _ _ref, where n corresponds to the slot in which the reported channel state information (CSI), an _CQI _ _ref corresponds to the smallest value, greater than or equal to X, which is indicated by information related to X; and transmitting channel state information (CSI) in a slot in which channel state information (CSI) is reported. 3. Base station containing: a receiving section configured to receive, from the terminal, terminal capability information related to the value (X) used to find a reference channel state information (CSI) resource; a transmission section configured to transmit, to the information terminal relating to the X, defining a slot nn _CQI _ _ref for the reference resource of the channel state information (CSI), wherein n corresponds to the slot in which the reported channel state information (CSI), an _CQI _ _ref corresponds to the smallest value greater than or equal to X as indicated by information related to X; wherein the receiving section is further configured to receive channel state information (CSI) in a slot in which channel state information (CSI) is reported. 4. Communication system containing a base station and a terminal, in which the terminal contains: a transmission section, configured to transmit to the base station information about the technical capabilities of the terminal related to the value (X) used to find the reference resource of the channel status information (CSI); a receiving section configured to receive information related to X from the base station; and a control section configured to measure channel state information (CSI) on the basis of the reference resource of the channel state information (CSI) in slot nn _CQI _ _ref, where n corresponds to the slot in which the reported channel state information (CSI), an _CQI _ _ref matches the smallest value greater than or equal to X as indicated by information related to X; wherein the transmitting section is further configured to transmit channel state information (CSI) in a slot in which channel state information (CSI) is reported; and base station contains: a receiving section configured to receive, from the terminal, terminal capability information related to X; a transmission section configured to transmit information related to X to the terminal; wherein the receiving section is further configured to receive channel state information (CSI) in a slot in which channel state information (CSI) is reported.

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